import React, { Component } from 'react';
import './App.css';
import logo from './logo.svg';
import ReactDOM from "react-dom";

//
const element = (
    <div className>
        <div className="App-header">
            <img src={logo} className="App-logo" alt="logo" />
            <h2>welcome</h2>
        </div>
        <p className="App-intro">
            to do
        </p>
    </div>
);

// 自定义组件
class App extends Component {
      render() {
      return element;
  }
}

export default App;
